如何获取字体大小或UIFont实例的粗体版本

Question

如何获取UIFont实例的字体大小？

或者,如果有人可以为UIFont实现此方法？

- (UIFont *)boldFont;

Answer 1

这是一个老答案,它不再是最好的解决方案,请参阅接受的答案.

-(UIFont *)boldFont{

//First get the name of the font (unnecessary, but used for clarity)
NSString *fontName = self.fontName;

//Some fonts having -Regular on their names. so we have to remove that before append -Bold / -BoldMT
fontName = [[fontName componentsSeparatedByString:@"-"] firstObject];

//Then append "-Bold" to it.
NSString *boldFontName = [fontName stringByAppendingString:@"-Bold"];

//Then see if it returns a valid font
UIFont *boldFont = [UIFont fontWithName:boldFontName size:self.pointSize];

//If it's valid, return it
if(boldFont) return boldFont;

//Seems like in some cases, you have to append "-BoldMT"
boldFontName = [fontName stringByAppendingString:@"-BoldMT"];
boldFont = [UIFont fontWithName:boldFontName size:self.pointSize];

//Here you can check if it was successful, if it wasn't, then you can throw an exception or something.
return boldFont;

}

Answer 2

要从UIFont实例访问字体大小,请使用

 @property(nonatomic, readonly) CGFloat pointSize

有更多属性可以告诉字体大小(对于上限,小等...)

capHeight,xHeight,pointSize 

使用下面的代码访问粗体字体

UIFont* myboldFont = [UIFont boldSystemFontOfSize:11];

Answer 3

UIFontDescriptor是非常强大的类,可用于获得您想要的字体的粗体版本.它应该是完全安全的和未来的证明,因为它只需要使用公共API并且不依赖于任何字符串修改.

这是Swift 3中的代码:

extension UIFont {

    func bold() -> UIFont? {
         let fontDescriptorSymbolicTraits: UIFontDescriptorSymbolicTraits = [fontDescriptor.symbolicTraits, .traitBold]
         let bondFontDescriptor = fontDescriptor.withSymbolicTraits(fontDescriptorSymbolicTraits)
         return bondFontDescriptor.flatMap { UIFont(descriptor: $0, size: pointSize) }
    }

}

这是objective-c中的代码:

@implementation UIFont (RABoldFont)

- (UIFont *)ra_boldFont
{
    UIFontDescriptor *fontDescriptor = [self fontDescriptor];
    UIFontDescriptorSymbolicTraits traits = fontDescriptor.symbolicTraits;
    traits = traits | UIFontDescriptorTraitBold;
    UIFontDescriptor *boldFontDescriptor = [fontDescriptor fontDescriptorWithSymbolicTraits:traits];
    return [UIFont fontWithDescriptor:boldFontDescriptor size:self.pointSize];
}

@end

Answer 4

这是查找字体大小的最简单方法

UIFont *anyFont;
//initialization and other stuff here

现在在某些时候你想找到它的大小

 CGFloat fontSize= [anyFont pointSize];